> USGS geologists do not consider "net energy" when computing
> the size of an energy resource.
[ ... ]
> According to Gever et al., 1991, p. 67, by 2040 it will
> require more energy to mine domestic coal than the energy recovered.
And you don't take into account changes in technology. Yes, in 2040, if we haven't found a more cost-effective way to get coal out of the ground (how are we doing today vs. 50 years ago?), it'll cost more to get it than it's worth.
But everything has this effect: 50 years ago, we could just have easily said:
] If present trends continue, the floorspace required for all the ] computers we'll need will exceed the surface area of the Pacific ] Ocean! There will be no place to put them all; we'll be up to ] our elbows in computers!
Of course the 'present trends' didn't continue; they increased geometrically! And yet ... we didn't have that problem.
> OIL SANDS
> According to Youngquist (1997), it currently takes more
> energy to mine oil sands than the amount of energy recovered. In
> other words, oil sands are already "depleted".
And what if this changes? That is, what if we find a way to get oil from oil sands that *doesn't* take more energy to mine than it recovers? Is it still depleted? This notation is barmy!
> OIL SHALE
> "As of 1997 no oil from oil shale is being produced in the
> U.S... or anywhere else.
My understanding is that oil from shale costs about $35/bbl right now; with $18 spot prices, why bother? What, are they expected to make it up in volume?
The point is: the resource is there, and when it becomes economical, it will be tapped. During the Gulf War, some of these resources were considered (until they realized the price hike to $40/bbl was to be short-lived ...).
/jordan